JAMB Mathematics Past Questions & Answers - Page 287

1,431.

In a basket of fruits, there are 6 grapes, 11 bananas and 13 oranges, if one fruit is chosen at random, what is the probability that the fruit is either a grape or a banana?

A.

\(\frac{17}{30}\)

B.

\(\frac{11}{30}\)

C.

\(\frac{6}{30}\)

D.

\(\frac{5}{30}\)

Correct answer is A

Pgrape or Pbanana = \(\frac{6}{30}\) + \(\frac{11}{30}\)

= \(\frac{17}{30}\)

1,432.

Find the difference between the range and the variance of the following set of numbers 4, 9, 6, 3, 2, 8, 10, 5, 6, 7 where \(\sum d^2\) = 60

A.

2

B.

3

C.

4

D.

6

Correct answer is A

Range : 10 - 2 = 8

Variance = \(\frac{\sum d^{2}}{n}\)

= \(\frac{60}{10}\)

= 6

8 - 6 = 2.

1,434.

If \(y = x(x^4 + x + 1)\), evaluate \(\int \limits_{0} ^{1} y \mathrm d x\).

A.

\(\frac{11}{12}\)

B.

1

C.

\(\frac{5}{6}\)

D.

zero

Correct answer is B

\(y = x(x^{4} + x + 1) = x^{5} + x^{2} + x\)

\(\int \limits_{0} ^{1} (x^{5} + x^{2} + x) \mathrm d x = \frac{x^{6}}{6} + \frac{x^{3}}{3} + \frac{x^{2}}{2}\)

= \([\frac{x^{6}}{6} + \frac{x^{3}}{3} + \frac{x^{2}}{2}]_{0} ^{1}\)

= \(\frac{1}{6} + \frac{1}{3} + \frac{1}{2}\)

= \(1\)

1,435.

Integrate \(\frac{1}{x}\) + cos x with respect to x

A.

-\(\frac{1}{x^2}\) + sin x + k

B.

x + sin x - k

C.

x - sin x + k

D.

-\(\frac{1}{x^2}\) - sin x + k

Correct answer is C

\(\int \frac{1}{x} + \cos x = ln x - \sin x + k\)